Abstract: The risk of sub-synchronous oscillations in wind farm with doubly-fed induction generators (DFIGs) connected to the grid via series capacitor compensated transmission line is well known and has been widely studied. However, the research on sub- and super-synchronous oscillations which can be observed in DFIGs integrated system without series capacitors is rarely availale in the literature. In this paper, eigenvalue analysis as well as electromagnetic transient simulation were applied to study of sub- and super-synchronous oscillation problem. The dominant unstable modes of the DFIGs integrated system without series compensation were investigated. The effects of operation conditions as well as control parameters on the stability of these dominant modes were analyzed. The oscillation scenarios dominated by GSC control, PLL, and RSC control, respectively, under weak grid connection were disclosed. By comparison with the case of DFIGs connected to grid via series compensated transmission line, the DIFGs integrated system related sub- and super –synchronous oscillation scenarios and the relevant mechanisms were clarified. This work can provide a reference for practical DFIGs integrated system oscillation analysis.